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tamnd's digital brain — notes, problems, research
41601 notes
I can’t reliably write a correct editorial yet because the full statement of Codeforces 103351H is not included in your prompt, and the problem page does not provide enough accessible detail in isolation.
Let $n ct cdots c1 ge 0$ with the constraints from exercise 57 and the additional condition $c{j+1} cj + 1 qquad (t j ge 1).$ Define the shifted variables $dj = cj - (j-1), qquad 1 le j le t.
I can write the full editorial, but I’m missing the actual problem statement for Codeforces 103351G - Digit analysis.
I can’t write a correct editorial for “Codeforces 103351E - The Best Present” because the actual problem statement is missing from your prompt. Right now there’s no information about what the input represents, what needs to be computed, or any constraints.
I’m missing the actual problem statement for Codeforces 103351D - Set game, and I can’t reliably reconstruct it from the title alone without risking inventing details.
The task is the classic arithmetic building block: we are given integer pairs, and for each pair we must output their sum. Each input line represents two numbers that should be combined directly, with no additional structure such as graphs or arrays.
I can’t produce a correct, problem-specific editorial yet because the actual statement of Codeforces 103351C - Simplux is missing from your prompt. Without the rules, input format, and constraints, any solution would be guesswork and very likely wrong.
Let $\mathcal{F}(N,t)$ denote a family of $N$ distinct $t$-combinations, and let $\kappa_t(N)$ be the extremal quantity defined in Section 7.
Let $n ct cdots c1 ge 0$ with the constraints from exercise 57 and the additional condition $c{j+1} cj + 1 qquad (t j ge 1).$ Define the shifted variables $dj = cj - (j-1), qquad 1 le j le t.
I can’t produce a correct editorial yet because the actual problem statement for Codeforces 103358D - “Гейзеры” is not included in your prompt, and it is not reliably recoverable from the references I found.
I could not reliably retrieve the exact statement of Codeforces problem 103358A - “Работа из дома” from the available archive sources.
I don’t have the actual statement of Codeforces 103358C - Игра с массивом available from the prompt, and I can’t reconstruct the problem reliably from the title alone without risking inventing details.
We are given a scenario where Jerry is dealing with a sequence of tasks, and each task carries some numeric information that affects how Jerry processes or schedules them.
I can’t reliably write a correct editorial without the actual problem statement for Codeforces 103359C - Мышеловки. Right now the prompt is missing all core information (what the traps/mouse-related mechanics are, what inputs represent, and what needs to be computed).
Let $n = s + t$ as in (1), and consider a $t$-combination $ct cdots c1$ with $n ct cdots c1 ge 0$ together with the additional adjacency restriction $c{j+1} cj + 1 qquad (t j ge 1).$ Define new integers $c'j = cj - (j-1), qquad 1 le j le t.
I can’t write a correct editorial for this yet because the actual problem statement for Codeforces 103359A - Survival and Chocolate is missing from your prompt.
Let $n = s + t$ as in (1), and consider a $t$-combination $ct cdots c1$ with $n ct cdots c1 ge 0$ together with the additional adjacency restriction $c{j+1} cj + 1 qquad (t j ge 1).$ Define new integers $c'j = cj - (j-1), qquad 1 le j le t.
Let $\kappa_t(N)$ denote the function defined in Section 7.
Let $\kappa_t(N)$ denote the function defined in Section 7.
Let $n = s + t$ as in (1), and consider a $t$-combination $ct cdots c1$ with $n ct cdots c1 ge 0$ together with the additional adjacency restriction $c{j+1} cj + 1 qquad (t j ge 1).$ Define new integers $c'j = cj - (j-1), qquad 1 le j le t.
Let a string $\alpha$ consist of symbols from ${+, -, 0}$ with exactly $t$ zeros and $s$ signs, where each nonzero symbol is either $+$ or $-$.
I can’t write a correct editorial for this yet because the actual problem statement for Codeforces 103360E - “Боевые дроиды” is missing from your message. Right now I don’t know: - what the input represents (graph, array, game, geometry, etc.
I can’t write a correct editorial yet because the actual problem statement is missing. Right now I only see the title “Codeforces 103360C - Древний замок”, but there are no details about what the input describes, what needs to be computed, or any constraints.
I can’t reliably write a correct editorial for this yet because the problem statement for Codeforces 103360B - “Джедайские вычисления” isn’t included in your prompt.
Let $n = s + t$ as in (1), and consider a $t$-combination $ct cdots c1$ with $n ct cdots c1 ge 0$ together with the additional adjacency restriction $c{j+1} cj + 1 qquad (t j ge 1).$ Define new integers $c'j = cj - (j-1), qquad 1 le j le t.
We are given a binary string representing a strip of cells. Some cells already contain a cross, marked as X, and the rest are empty, marked as .. The key constraint is that no two crosses are allowed to be adjacent, meaning we can never have XX in neighboring positions.
We are given a small collection of Christmas trees, each with a positive integer height. The task is to pick three different trees such that all three have exactly the same height. The output is the indices of those three trees.
We are given two collections of strings, one called array a and the other called array b. The task is to pick a single non-empty string s that satisfies two conditions at the same time. First, s must appear as a substring in every string of a.
The game is played on a fixed line of 20 cells. Each player secretly places four contiguous ships of lengths 1, 2, 3, and 4.
Codeforces 103361J: Иван и дороги
We are given a single day schedule involving two time moments and two durations. First, we know when a traveler leaves home, expressed as hours and minutes. From that moment, a navigation system says the travel time to the airport is a fixed number of minutes.
We are given a directed graph whose vertices are lakes and whose edges are rivers flowing from one lake to another.
An (s, t)-combination $c4 c3 c2 c1$ with $t=4$ is a strictly decreasing 4-tuple $$n c4 c3 c2 c1 ge 0,$$ and the condition $c4 - c1 < m$ is equivalent to requiring that all selected elements lie in an interval of length $m-1$.
We are given a rectangle of size $m times n$, and we want to completely tile it using smaller rectangles of fixed size $1 times k$.
We are maintaining an array of integers that changes over time. Alongside updates, we are repeatedly asked a very specific query: given a segment of the array and a number x, we must count how many elements inside that segment divide x exactly.
An (s, t)-combination $c4 c3 c2 c1$ with $t=4$ is a strictly decreasing 4-tuple $$n c4 c3 c2 c1 ge 0,$$ and the condition $c4 - c1 < m$ is equivalent to requiring that all selected elements lie in an interval of length $m-1$.
The problem describes a two-player game built around repeated division of numbers. We start with a multiset of integers, and players take turns selecting a number and replacing it by one of its proper divisors according to fixed rules of the game.
We start with a single digit x. From this digit we repeatedly generate new digits by multiplying the current digit by 3 and taking the last decimal digit of the result, then appending it to the right side of the number written on the board.
We are given a rectangular board with integer side lengths. The task is to partition this rectangle into smaller squares by cutting along grid lines.
An (s, t)-combination $c4 c3 c2 c1$ with $t=4$ is a strictly decreasing 4-tuple $$n c4 c3 c2 c1 ge 0,$$ and the condition $c4 - c1 < m$ is equivalent to requiring that all selected elements lie in an interval of length $m-1$.
We are given several line segments floating above an infinite horizontal ground line, which we can think of as the x-axis. Each segment represents a “rainscreen” placed somewhere in the plane, and rain falls strictly vertically downward from infinity.
An (s, t)-combination $c4 c3 c2 c1$ with $t=4$ is a strictly decreasing 4-tuple $$n c4 c3 c2 c1 ge 0,$$ and the condition $c4 - c1 < m$ is equivalent to requiring that all selected elements lie in an interval of length $m-1$.
We are simulating how a cache behaves under a Least Recently Used policy, but instead of directly simulating it for a fixed cache size, we are asked a reverse question: among all possible cache capacities, we want the smallest capacity such that the cache produces at least K…
An (s, t)-combination $c4 c3 c2 c1$ with $t=4$ is a strictly decreasing 4-tuple $$n c4 c3 c2 c1 ge 0,$$ and the condition $c4 - c1 < m$ is equivalent to requiring that all selected elements lie in an interval of length $m-1$.
We are given a tree of n students. Each student lives at a node, and each edge represents a bidirectional road with a travel time. Every student also has a personal time ai, meaning how long they need to finish homework on their own if they never copy from anyone else.
We are given an array of positive integers. For each query, we focus on a contiguous segment of this array and try to find a single integer greater than one that divides as many numbers inside that segment as possible.
We are given an infinite integer grid. There are two kinds of pieces: several pawns controlled by us, and a single gold general controlled by the opponent. Each pawn starts at a fixed coordinate, while the gold general starts at the origin. The game evolves in alternating turns.
We are given a multiset of integers, and we are allowed to rearrange them into any order. After rearrangement, we must guarantee the existence of at least one value, call it $x$, such that all occurrences of $x$ are sufficiently far apart: any two positions containing $x$ must…
An (s, t)-combination $c4 c3 c2 c1$ with $t=4$ is a strictly decreasing 4-tuple $$n c4 c3 c2 c1 ge 0,$$ and the condition $c4 - c1 < m$ is equivalent to requiring that all selected elements lie in an interval of length $m-1$.
We are given a stack of horizontal segments indexed from 1 to n, where the i-th segment lies at vertical level y = −i and allows us to choose a single point with x-coordinate anywhere inside a closed interval [li, ri].
We are given a positive rational number represented as a reduced fraction x/y, and we are asked to express it as a finite continued fraction.
An (s, t)-combination $c4 c3 c2 c1$ with $t=4$ is a strictly decreasing 4-tuple $$n c4 c3 c2 c1 ge 0,$$ and the condition $c4 - c1 < m$ is equivalent to requiring that all selected elements lie in an interval of length $m-1$.
I cannot reliably reconstruct the solution to Codeforces 103367J - “Идеальное покрытие треугольниками” from the data available in your prompt or from partial indexed references.
I can’t reliably write a correct editorial without the actual problem statement. Right now the prompt only contains the title, but no description of the task, inputs, outputs, or constraints.
I can’t reliably reconstruct Codeforces 103367H (“Парное пугание”) from the title alone, and writing a correct editorial without the full statement would almost certainly drift into guessing.
I cannot safely write a correct editorial yet because the full problem statement is not available in the prompt, and the content we extracted from the page does not fully describe the task in a reliable way.
I cannot safely write a correct editorial yet because the problem statement I initially retrieved was incorrectly matched to the given ID.
I can’t write a correct editorial for this yet because the actual problem statement is missing. Right now I only see the title “Нужно меньше дорог!” but no description of the graph, operations, or what is being asked.
I can absolutely write this editorial in the exact style you specified, but I’m missing the one thing that determines everything: the actual problem statement.
Let the degree-$,(t-1),$ combinatorial representation (57) of a positive integer $N$ be written in the form N = \binom{n_t}{t} + \binom{n_{t-1}}{t-1} + \cdots + \binom{n_v}{v}, \qquad n_t > n_{t-1} >...
I can’t reliably write a correct editorial for this without the actual problem statement. “Codeforces 103367B - Устрашающий палиндром” isn’t enough on its own, and I don’t have the text of the task (input/output definition, constraints, or…
I can’t write a correct Codeforces editorial for “103367C - Патруль экзорцистов” without the actual problem statement.
I can’t write a correct Codeforces editorial here because the actual problem statement is missing. Right now there’s no information about what the input describes, what needs to be computed, or even the constraints, so any solution would be guesswork.
Let $C(n,t,m)$ denote the graph whose vertices are all $t$-combinations $ctldots c1$ with $$nctcdotsc1ge 0,qquad ct-c1<m,$$ and in which two vertices are adjacent when they differ in exactly one entry, that is, one replacement $cj leftarrow cj'$ preserves strict increase and…
I cannot reliably produce a correct editorial yet because the problem statement for Codeforces 103369I - Трудная задача is not available from the provided context, and I also cannot safely reconstruct it from memory or assumptions without risking inventing details.
I don’t have the actual problem statement for Codeforces 103369H (“Еще одна игра с фишками”) in the prompt, so I can’t reliably reconstruct the rules, operations, or intended solution.
We are given an array of integers and a single allowed operation that can be used at most once. The operation lets us pick any subset of positions and add the same positive value $k$ to all chosen elements.
I can’t complete a correct editorial for Codeforces 103369F - Difficult mountain yet because the actual problem statement is missing from your prompt.
I cannot reliably reconstruct Codeforces 103369E “Онлайн-курс по физкультуре” from the available context alone because the actual problem statement is not present in your prompt, and Codeforces problems with this numbering are not part of the standard…
I can write the full editorial in your required format, but the problem statement for Codeforces 103369D - “Оптимальная вставка” is missing from your message.
We are given a static array of numbers, and then a sequence that tells us the order in which elements of this array get “removed” one by one. After each removal, we are left with several disjoint contiguous segments of still-alive elements.
I can’t write a correct Codeforces editorial without the actual problem statement. Right now the prompt only includes the template, but the core part is empty: For a problem like “103369C - Полёт над озером”, the full description is essential because the…
Let $C(n,t,m)$ denote the graph whose vertices are all $t$-combinations $ctldots c1$ with $$nctcdotsc1ge 0,qquad ct-c1<m,$$ and in which two vertices are adjacent when they differ in exactly one entry, that is, one replacement $cj leftarrow cj'$ preserves strict increase and…
Let the degree-$,(t-1),$ combinatorial representation (57) of a positive integer $N$ be written in the form N = \binom{n_t}{t} + \binom{n_{t-1}}{t-1} + \cdots + \binom{n_v}{v}, \qquad n_t > n_{t-1} >...
I can’t produce a correct editorial yet because the actual problem statement for Codeforces 103371M - Yet Another Range Query Problem is missing from your prompt.
The problem statement for “Codeforces 103371K - Three Competitions” is missing from your message, so there isn’t enough information to write a correct editorial.
I cannot safely reconstruct a correct editorial yet because the actual statement of Codeforces 103371J - Periodic Ruler is not visible from the available context.
Let $C(n,t,m)$ denote the graph whose vertices are all $t$-combinations $ctldots c1$ with $$nctcdotsc1ge 0,qquad ct-c1<m,$$ and in which two vertices are adjacent when they differ in exactly one entry, that is, one replacement $cj leftarrow cj'$ preserves strict increase and…
I don’t have the actual problem statement for Codeforces 103371I in your prompt, and I can’t reliably reconstruct it from the title alone without risking inventing details.
I don’t have the actual statement for Codeforces 103371H - Or Machine, and without it any “full editorial” would be guesswork rather than a correct derivation.
The problem statement is missing, so I can’t reliably derive the solution or write a correct editorial for it. “Codeforces 103371G - Lamb’s Respite” alone isn’t enough to reconstruct the task, and guessing would risk inventing constraints, operations, or even the wrong…
We are given a structured coin system with multiple coin types. Each coin type has a value and a weight, and coin values are strictly increasing in such a way that each value is a multiple of the previous one.
I can’t write a correct editorial for this yet because the actual problem statement is missing. “Codeforces 103371F - Hedgehog Graph” alone isn’t enough to reconstruct the graph definition, operations, or required output, and guessing would almost certainly produce a…
The problem statement is missing from your prompt (the sections for Problem Statement, Input, and Output are empty). I can’t safely reconstruct Codeforces 103371D from that, and writing a full editorial without the actual rules would risk inventing details.
We are given several pipeline designs. Each design is a weighted tree over the same set of buildings. Every pipe connects two buildings and has a durability value. For any design, consider any two buildings. There is a unique path between them in the tree.
The editorial request is missing the actual problem statement, so there’s no way to correctly reconstruct the algorithm or constraints.
I can’t write a correct editorial for this yet because the actual problem statement (what “Organizing Beads” is asking, input/output format, constraints) is missing from your message. Right now I only have the title, so any solution would be a guess and very likely wrong.
I can’t reliably write a correct editorial for Codeforces 103372J - Three Competitions because the problem statement isn’t included here, and I don’t have access to the original contest archive from just the ID alone.
Let $C(n,t,m)$ denote the graph whose vertices are all $t$-combinations $ctldots c1$ with $$nctcdotsc1ge 0,qquad ct-c1<m,$$ and in which two vertices are adjacent when they differ in exactly one entry, that is, one replacement $cj leftarrow cj'$ preserves strict increase and…
I can’t write a correct editorial for Codeforces 103372I - Cities Solitaire because the actual problem statement is missing from your prompt.
Let the ternary reflected Gray code on $n$ digits be the sequence of all $n$-tuples $a = a_{n-1}\dots a_1a_0,\qquad a_i \in \{0,1,2\},$ constructed in the standard reflected recursive way, so consecut...
I don’t have the actual statement of Codeforces 103372H - Periodic Ruler in your prompt, so I can’t reliably reconstruct the problem, constraints, or required solution.
I can’t reliably reconstruct Codeforces 103372G (“Or Machine”) from just the name, and I don’t want to invent a problem statement and end up writing an incorrect editorial.
I can’t reliably write an editorial for Codeforces 103372F - Inspection yet because the actual problem statement (what “inspection” refers to, the structure of the input, and what is being optimized or computed) is missing from your prompt.
The problem statement section is empty, so I don’t actually know what “Codeforces 103372D - Equivalent Pipelines” is asking.
I can’t write a correct editorial yet because the actual problem statement is missing. Right now I only know the title “Flowerbed Redecoration”, but there are no details about: - what the input represents - what transformations or constraints exist - what needs to be…
I can write the full editorial in your required format, but I’m missing the actual problem content for CF 103372B - Automatic Sprayer 2.
I’m missing the actual problem statement for Codeforces 103372A - Histogram Sequence 3, so I can’t reliably reconstruct the task, constraints, or edge cases.
Let $C(n,t,m)$ denote the graph whose vertices are all $t$-combinations $ctldots c1$ with $$nctcdotsc1ge 0,qquad ct-c1<m,$$ and in which two vertices are adjacent when they differ in exactly one entry, that is, one replacement $cj leftarrow cj'$ preserves strict increase and…
We are given an undirected graph where each node carries a 16-bit integer value. Every edge contributes a cost equal to the Hamming distance between the two endpoint values, meaning the number of bit positions where the two node values differ.